package server;

import org.dom4j.Document;
import org.dom4j.DocumentException;
import org.dom4j.Element;
import org.dom4j.io.SAXReader;

import java.io.*;
import java.net.ServerSocket;
import java.net.Socket;
import java.util.HashMap;
import java.util.List;
import java.util.Map;
import java.util.concurrent.*;

/**
 * Minicat的主类
 */
public class Bootstrap {

    /**
     * 定义socket监听的端口号
     */
    private int port = 8080;

    public int getPort() {
        return port;
    }

    public void setPort(int port) {
        this.port = port;
    }

    //项目路径
    private String webappsPath = "";
    //host : 127.0.0.1  context : demo   wrapper : /lagou
    private Map<String, Map<String, Map<String, HttpServlet>>> hosts = new HashMap<>();

    /**
     * Minicat启动需要初始化展开的一些操作
     */
    public void start() throws Exception {

        // 加载解析相关的配置，web.xml
        loadServlet();


        // 定义一个线程池
        int corePoolSize = 10;
        int maximumPoolSize = 50;
        long keepAliveTime = 100L;
        TimeUnit unit = TimeUnit.SECONDS;
        BlockingQueue<Runnable> workQueue = new ArrayBlockingQueue<>(50);
        ThreadFactory threadFactory = Executors.defaultThreadFactory();
        RejectedExecutionHandler handler = new ThreadPoolExecutor.AbortPolicy();


        ThreadPoolExecutor threadPoolExecutor = new ThreadPoolExecutor(
                corePoolSize,
                maximumPoolSize,
                keepAliveTime,
                unit,
                workQueue,
                threadFactory,
                handler
        );

        /*
            完成Minicat 1.0版本
            需求：浏览器请求http://localhost:8080,返回一个固定的字符串到页面"Hello Minicat!"
         */
        ServerSocket serverSocket = new ServerSocket(port);
        System.out.println("=====>>>Minicat start on port：" + port);

        System.out.println("=========>>>>>>使用线程池进行多线程改造");
        /*
            多线程改造（使用线程池）
         */
        while (true) {
            Socket socket = serverSocket.accept();
            RequestProcessor requestProcessor = new RequestProcessor(socket, hosts, webappsPath);
            threadPoolExecutor.execute(requestProcessor);
        }


    }


    private Map<String, HttpServlet> servletMap = new HashMap<String, HttpServlet>();

    private void loadServlet() {
        InputStream resourceAsStream = this.getClass().getClassLoader().getResourceAsStream("server.xml");
        SAXReader saxReader = new SAXReader();


        try {
            //解析server.xml
            Document document = saxReader.read(resourceAsStream);
            Element rootElement = document.getRootElement();
            List<Element> portNodes = rootElement.selectNodes("//Connect");
            Element element = (Element) rootElement.selectSingleNode("//Connect");
            port = Integer.parseInt(element.attributeValue("port"));

            List<Element> hostsEle = rootElement.selectNodes("//Host");//获取host

            for (int i = 0; i < hostsEle.size(); i++) {
                String hostName = hostsEle.get(i).attributeValue("name");

                //项目集
                Map<String, Map<String, HttpServlet>> contexts = new HashMap<>();
                webappsPath = hostsEle.get(i).attributeValue("appBase");//host对应项目路径路径
                webappsPath = webappsPath.replaceAll("\\\\", "/");

                File file = new File(webappsPath);
                if (file.exists() && !file.isFile()) {

                    File[] files = file.listFiles();
                    for (int j = 0; j < files.length; j++) {
                        //项目
                        Map<String, HttpServlet> context = new HashMap<>();
                        String webPath = files[j].getPath();//项目路径
                        //单个项目文件名
                        String fileName = webPath.replace(file.getPath() + "\\", "");
                        //读取web.xml文件
                        File webXml = new File(webPath + "\\web.xml");
                        InputStream resourceAsStreamWeb = new FileInputStream(webXml);
                        SAXReader saxReaderWeb = new SAXReader();


                        Map<String, HttpServlet> wrapper = new HashMap<String, HttpServlet>();
                        //解析各个项目web.xml
                        try {
                            Document documentWeb = saxReaderWeb.read(resourceAsStreamWeb);
                            Element rootElementWeb = documentWeb.getRootElement();

                            List<Element> selectNodes = rootElementWeb.selectNodes("//servlet");
                            for (int k = 0; k < selectNodes.size(); k++) {


                                Element elementWeb = selectNodes.get(k);
                                // <servlet-name>lagou</servlet-name>
                                Element servletnameElement = (Element) elementWeb.selectSingleNode("servlet-name");
                                String servletName = servletnameElement.getStringValue();
                                // <servlet-class>server.LagouServlet</servlet-class>
                                Element servletclassElement = (Element) elementWeb.selectSingleNode("servlet-class");

                                String servletClass = servletclassElement.getStringValue();//class绝对路径
                                // 根据servlet-name的值找到url-pattern
                                Element servletMapping = (Element) rootElementWeb.selectSingleNode("/web-app/servlet-mapping[servlet-name='" + servletName + "']");
                                // /lagou
                                String urlPattern = servletMapping.selectSingleNode("url-pattern").getStringValue();
                                String pakageDir = webPath.replaceAll("\\\\", "/");
                                MyClassLoader loader = new MyClassLoader(pakageDir + "/");
                                Class<?> clazz = loader.findClass(servletClass);
                                wrapper.put(urlPattern, (HttpServlet) clazz.getClassLoader().loadClass(servletClass).newInstance());
                            }

                        } catch (DocumentException e) {
                            e.printStackTrace();
                        } catch (IllegalAccessException e) {
                            e.printStackTrace();
                        } catch (InstantiationException e) {
                            e.printStackTrace();
                        } catch (ClassNotFoundException e) {
                            e.printStackTrace();
                        }


                        //context.put(fileName,);
                        contexts.put(fileName, wrapper);
                    }


                }

                if ("localhost".equalsIgnoreCase(hostName)) {
                    hosts.put("127.0.0.1", contexts);//增加127.0.0.1 对应 localhost
                }
                hosts.put(hostName, contexts);
            }
        } catch (DocumentException e) {
            e.printStackTrace();
        } catch (FileNotFoundException e) {
            e.printStackTrace();
        }

    }

    /**
     * Minicat得启动入口
     */

    public static void main(String[] args) {
        Bootstrap bootStrap = new Bootstrap();
        try {
            bootStrap.start();
        } catch (IOException e) {
            e.printStackTrace();
        } catch (Exception e) {
            e.printStackTrace();
        }
    }

}